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United States Patent 5,500,060
Holt ,   et al. March 19, 1996

Energetic plasticized propellant

Abstract

An energetic composition comprising the following components in the following relative proportions: Component A: from 5% to 25% by weight of a polymeric binder; Component B: from 65% to 90% by weight of a highly energetic filler comprising at least one heteroalicyclic nitramine compound; and Component C: from 1% to 15% by weight of a plasticiser which comprises at least one nitroaromatic compound; the percentages by weight of Components A, B and C adding to 100%.


Inventors: Holt; Ronald B. (Waltham Abbey, GB2); Phillips; John C. M. (Bishops Stortford, GB2)
Assignee: Royal Ordnance plc (London, GB2)
Appl. No.: 039893
Filed: March 29, 1993
Foreign Application Priority Data

Jul 04, 1986[GB]8616322

Current U.S. Class: 149/19.1; 149/19.7; 149/19.8; 149/92; 149/105; 149/106
Intern'l Class: C06B 045/10
Field of Search: 149/19.1,19.7,19.8,92,105,106


References Cited
U.S. Patent Documents
3706609Dec., 1972Voigt, Jr., et al.149/105.
3909323Sep., 1975Flanagan et al.149/19.
4092188May., 1978Lovelace149/92.
4284442Aug., 1981Voigt149/19.
4394197Jul., 1983Kabik et al.149/92.
4570540Feb., 1986Bell149/19.
4657607Apr., 1987Perotto et al.149/92.
5043031Aug., 1991Redecker et al.149/19.
5067996Nov., 1991Lundstrom et al.149/92.

Primary Examiner: Miller; Edward A.
Attorney, Agent or Firm: Stevens, Davis, Miller & Mosher

Parent Case Text



This application is a continuation of application Ser. No. 07/754,933, filed Sep. 3, 1991, now abandoned; which in turn is a continuation of application Ser. No. 07/629,111, filed Dec. 19, 1990, now abandoned; which in turn is a continuation of application Ser. No. 07/466,708, filed Dec. 28, 1989, now abandoned; which in turn is a continuation of application Ser. No. 07/300,646, filed Jan. 5, 1989, now abandoned; which in turn is a continuation of application Ser. No. 07/081,799, filed Jul. 6, 1987, now abandoned.
Claims



We claim:

1. An energetic composition comprising the following components in the following relative properties:

Component A: from 5% to 25% by weight of a polymeric binder;

Component B: from 65% to 90% by weight of a highly energetic filler comprising at least one heteroalicyclic nitramine compound; and

Component C: from 1% to 15% by weight of a plasticiser which comprises two or more nitroaromatic compounds; the percentages by weight of Components A, B and C adding to 100%.

2. An energetic composition comprising the following components in the following relative proportions:

Component A: from 5% to 25% by weight of a polymeric binder;

Component B: from 65% to 90% by weight of a highly energetic filler comprising at least one heteralicyclic nitramine compound; and

Component C: from 1% to 15% by weight of a plasticizer which comprises:

a mixture of dinitroethylbenzene and trinitroethylbenzene containing:

dinitroethylbenzene 50 to 64 percent by weight

trinitroethylbenzene 36 to 50 percent by weight;

the percentages by weight of Components A, B and C adding to 100%.
Description



The present invention relates to energetic materials, particularly polymer bonded explosives and gun propellants and compositions suitable therefor.

Gun propellants have for many years been produced from compositions containing blends of nitrocellulose and nitroglycerine and are therefore known as double base materials. In some cases additional energetic ingredients such as picrite are added and the propellants are known as triple compositions. For high energy applications, e.g. the propulsion of kinetic energy projectiles from an armoured tank gun, highly energetic components such as nitramines have been included in double and triple base compositions.

Double and triple base compositions, particularly for high energy applications, suffer from the disadvantage that they are highly vulnerable to unwanted ignition when subjected in a hostile environment to attack by an energetic projectile, e.g. a projectile comprising a shaped warhead charge.

Recent approaches to the problem of vulnerability have involved the development of compositions which are essentially non-double base or-triple base systems. Although such systems can provide reduced vulnerability this is, in general terms, obtained at the expense of propellant energy.

It is an object of the present invention to provide improved insensitive energetic materials, especially plastic bonded explosives and gun propellant compositions for low vulnerability applications.

According to the present invention there is provided an energetic composition comprising the following components in the following relative proportions:

Component A: from 5% to 25% by weight of a polymeric binder;

Component B: from 65% to 90% by weight of a highly energetic filler comprising at least one heteroalicyclic nitramine compound; and

Component C: from 1% to 15% by weight of a plasticiser which comprises at least one nitroaromatic compound; the percentages by weight of Components A, B and C adding to 100%.

In compositions according to the present invention Component B essentially provides the high energy capability of the composition (although Component C makes and optionally Component A may make a minor contribution), Component A provides the required structural binder properties and Component C provides processibility enabling mixtures to be formed together with Components A and B and which may be worked into a suitable dough-like material which may be pressed or extruded to form suitable products, e.g., propellants. The mutual combination of these components is specially selected in compositions according to the present invention because of the unexpected advantages such a combination provides as follows.

We have found that compositions according to the present invention can be suitably processed to provide energetic materials, e.g., for use propellants which unexpectedly and beneficially can show an improved vulnerability but without a corresponding decrease in energy normally associated with such an improvement.

For example, propellant compositions embodying the present invention generally have a high ignition temperature and possess also the beneficial properties of relatively low flame temperatures for the level of energy involved, thereby affording the possibility of reduced barrel erosion, as well as a relatively low burning rate, the latter property beneficially allowing propellants to be made with small web sizes as described below. The compositions according to the present invention therefore can have a combination of properties which are especially suitable for the formulation of propellants for low vulnerability applications.

Preferably Component A comprises from 10% to 25% by weight, Component B comprises 70% to 90% by weight and Component C comprises 3% to 12% by weight, of the said composition.

Component C preferably comprises one or more compounds which melt at a temperature less than 100.degree. C. and desirably is a liquid at room temperature (20.degree. C.). Preferably, the or each said nitro compound of Component C is a monocyclic nitroaromatic compound; it may be a mono-nitro compound but preferably is a di- or tri-nitro compound or a mixture thereof.

Especially suitable as compounds for use in or as Component C are di- and tri-nitro benzenes or alkyl- or alkoxy-benzenes optionally containing substituent groups in the aromatic ring or in the alkyl or alkoxy group(s). For example, the compound may be a di- or tri-nitro derivative of an optionally substituted alkyl- or alkoxy-benzene containing from 1 to 3 optionally substituted alkyl and/or alkoxy groups each having from 1 to 4 carbon atoms. The compound may for instance be a di- or tri-nitro derivative of an optionally substituted toluene, ethylbenzene, propylbenzene, butylbenzene, xylene, methylethylbenzene, diethylbenzene or mesitylene or one of the other families to which the compounds listed below belong.

As optional substituents for the aromatic ring in addition to nitro group(s) and alkyl or alkoxy group(s) where present in the said nitroaromatic compound(s) of Component C, are preferred groups other than halogens selected from OH, SH, N.sub.3, NR.sub.1 R.sub.2, CO.OR.sub.3 or O.OCR.sub.4 where R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently H or a simple alkyl or alkoxy (containing from 1 to 4 carbon atoms) or phenyl.

Component C may for example comprise one or more of the following known compounds (where M.P./.degree. C. is the melting point in degrees Celsius):

    ______________________________________
    Compound
    No.     Name                   M.P./.degree.C.
    ______________________________________
    1       1-amino-2,4-dimethyl-3-nitrobenzene
                                   81-82
    2       1-amino-3,4-dimethyl-2-nitrobenzene
                                   65-66
    3       1-amino-3,5-dimethyl-2-nitrobenzene
                                   56
    4       2-amino-1,3-dimethyl-4-nitrobenzene
                                   81-82
    5       2-amino-1,5-dimethyl-3-nitrobenzene
                                   76
    6       5-amino-1,2-dimethyl-3-nitrobenzene
                                   74-75
    7       1-amino-2-methoxy-3-nitrobenzene
                                   67
    8       1,3-dihydroxy-2-nitrobenzene
                                   87-88
    9       1,2-dimethoxy-3-nitrobenzene
                                   64-65
    10      1,2-dimethoxy-4-nitrobenzene
                                   98
    11      1,3-dimethoxy-2-nitrobenzene
                                   89
    12      1,4-dimethoxy-2-nitrobenzene
                                   72-73
    13      2,4-dimethoxy-l-nitrobenzene
                                   76-77
    14      1,2-dimethyl-3,4-dinitrobenzene
                                   82
    15      1,2-dimethyl-3,5-dinitrobenzene
                                   77
    16      1,3-dimethyl-2,5-dinitrobenzene
                                   101
    17      1,4-dimethyl-2,3-dinitrobenzene
                                   93
    18      2,3-dimethyl-1,4-dinitrobenzene
                                   89-90
    19      1,2-dimethyl-4-hydroxy-5-nitrobenzene
                                   87
    20      1,3-dimethyl-2-hydroxy-4-nitrobenzene
                                   99-100
    21      1,4-dimethyl-2-hydroxy-3-nitrobenzene
                                   34-35
    22      1,5-dimethyl-2-hydroxy-3-nitrobenzene
                                   73
    23      1,5-dimethyl-3-hydroxy-2-nitrobenzene
                                   66-66.5
    24      2,5-dimethyl-1-hydroxy-3-nitrobenzene
                                   91
    25      1,2-dimethyl-3-nitrobenzene
                                   15
    26      1,2-dimethyl-4-nitrobenzene
                                   30-31
    27      1,3-dimethyl-2-nitrobenzene
                                   13
    28      1,3-dimethyl-5-nitrobenzene
                                   75
    29      1,4-dimethyl-2-nitrobenzene
                                   --
    30      2,4-dimethyl-1-nitrobenzene
                                   9
    31      1,3-dinitrobenzene     90
    32      1,3-dinitro-2-ethoxybenzene
                                   59.5-60.5
    33      1,3-dinitro-5-ethoxybenzene
                                   97.5
    34      1,4-dinitro-2-ethoxybenzene
                                   96-98
    35      2,4-dinitro-1-ethoxybenzene
                                   86-87
    36      1,3-dinitro-5-isopropyl-4-hydroxy-
                                   55.5
    6-methylbenzene
    37      1,2-dinitro-4-methoxybenzene
                                   71
    38      1,3-dinitro-5-methoxybenzene
                                   205.5
    39      1,4-dinitro-2-methoxybenzene
                                   97
    40      2,4-dinitro-1-methoxybenzene
                                   94.5-95.5
    41      2,4-dinitro-1,3,5-trimethyl-benzene
                                   86
    42      1-ethoxy-2-nitrobenzene
                                   2
    43      1-ethoxy-4-nitrobenzene
                                   60
    44      1-ethyl-2-nitrobenzene -23
    45      1-ethyl-3-nitrobenzene --
    46      1-ethyl-4-nitrobenzene -12
    47      1-isobutoxy-2-nitrobenzene
                                   (oil)
    48      4-isopropyl-1-methyl-2-nitrobenzene
                                   --
    49      1-isopropyl-2-nitrobenzene
                                   --
    50      1-isopropyl-4-nitrobenzene
                                   --
    51      1-mercapto-2-nitrobenzene
                                   58.5
    52      1-mercapto-4-nitrobenzene
                                   79
    53      1-methoxy-2-nitrobenzene
                                   10
    54      1-methoxy-3-nitrobenzene
                                   38-39
    55      1-methoxy-4-nitrobenzene
                                   54
    56      2-methoxy-1,3,5-trinitrobenzene
                                   69
    57      nitrobenzene           5.7
    58      1-nitro-2-triazobenzene
                                   53-55
    59      1-nitro-3-triazobenzene
                                   56
    60      1-nitro-4-triazobenzene
                                   75
    61      1-nitro-2,3,5-trimethylbenzene
                                   20
    62      1-nitro-2,4,5-trimethylbenzene
                                   71
    63      2-nitro-1,3,5-trimethylbenzene
                                   44
    64      1,2,4-trinitrobenzene  61-62
    65      1,3,5-trinitrobenzene  --
    66      N-(2-nitrophenyl)-benzamide
                                   98
    67      2-nitrophenyl benzoate 85
    68      3-nitrophenyl benzoate 71-72
    69      4-nitrophenyl benzoate 94-95
    70      2,4-dinitrotoluene     71
    71      2,5-dinitrotoluene     53
    72      2,6-dinitrotoluene     66
    73      3,4-dinitrotoluene     58
    74      2,4-dinitro-6-hydroxytoluene
                                   86
    75      3,5-dinitro-4-hydroxytoluene
                                   85
    76      2-hydroxy-3,4,5-trinitrotoluene
                                   102
    77      3-hydroxy-2,4,6-trinitrotoluene
                                   109-110
    78      2,4,6-trinitrotoluene  82
    ______________________________________


Preferably, at least 50% by weight of Component C comprises one or more alkyl substituted monocyclic dinitrobenzenes, e.g. selected from dinitrotoluenes, dinitroethylbenzenes and dinitropropylbenzenes.

Nitroaromatic compounds as described above have been found to provide energetic plasticisers which are compatible with nitramine energetic fillers and are highly suitable for use in processing mixtures of such fillers with polymeric binders. Preferably, the nitroaromatic plasticiser has an ignition temperature greater than 200.degree. C.

Nitroaromatic compounds as described above are known or may be made by well known methods.

For example, in the production of nitro derivatives of alkylbenzenes the appropriate alkylbenzene is treated with concentrated nitric and sulphuric acid at a temperature less than 40.degree. C. Where the product obtained is a mixture of nitro compounds, e.g. containing dinitro- and trinitro derivatives, such a mixture may itself be suitable for use in or as Component C.

Although Component C desirably comprises one or more monocyclic nitroaromatic compounds, e.g. so that the monocyclic nitro compound(s) forms at least 50 per cent by weight of Component C, it may also include one or more nitroaromatic compounds containing more than one aromatic ring, e.g. one or more of the 2-ring esters listed above or one or more nitro derivatives of biphenyl, naphthalene diphenylmethane, bibenzyl or stilbene preferably containing two or three nitro groups in each ring. An example is 2,2',4,4',6,6'-hexanitrostilbene.

Although Component C is preferably constituted entirely by nitroaromatic compounds as described above it could also include other energetic and non-energetic plasticisers as optional additives. For example, Component C may additionally include a quantity of one or more known energetic plasticisers such as GAP (glycidyl azide polymer), BDNPA/F (bis-2,2-dinitropropylacetal/formal), dimethylmethylene dinitroamine, bis(2,2-dinitropropyl)formal, bis(2,2,2-trinitroethyl)formal, bis(2-fluoro-2,2-dinitroethyl)formal, diethylene glycol dinitrate, glycerol trinitrate, glycol trinitrate, triethylene glycol dinitrate, tetrethylene glycol dinitrate, trimethylolethane trinitrate, butanetriol trinitrate, or 1,2,4-butanetriol trinitrate. Alternatively, or in addition, Component C may include one or more known non-energetic plasticisers such as dialkyl esters of adipic or phthalic acid, e.g., dibutyl phthalate, or diethyl phthalate, triacetin, tricresyl phosphate, polyalkylene glycols and their alkyl ether derivatives, e.g. polyethylene glycol, polypropylene glycol, and diethylene glycol butylether. However, preferably at least 50% desirably at least 75% by weight of Component C is constituted by one or more nitroaromatic compounds.

In the composition according to the present invention Component A may be any suitable polymer binder. It may comprise an inert binder material, an energetic binder material or a blend of inert and energetic binder materials. However, generally speaking, increasing the energetic nature of the binder increases the sensitiveness and-explosiveness of the energetic material formed therefrom. Therefore employed binders which are energetic are desirably not highly energetic. For example where the binder comprises a blend of inert and energetic materials the inert material preferably forms at least 50% by weight of the binder.

Examples of suitable inert or non-energetic binder materials are cellulosic materials such as esters, e.g. cellulose acetate, cellulose acetate butyrate, polyurethanes, polyesters, polybutadienes, polyethylenes, polyvinyl acetate and blends and/or copolymers thereof.

Examples of suitable energetic binder materials are nitrocellulose, polyvinyl nitrate, nitroethylene, nitroallyl acetate, nitroethyl acrylate, nitroethyl methacrylate, trinitroethyl acrylate, dinitropropyl acrylate, C-nitropolystyrene and its derivatives, polyurethanes with aliphatic C- and N- nitro groups, polyesters made from dinitrocarboxylic acids and dinitrodiols.

We prefer cellulosic materials for Component A comprising 0 to 60 per cent by weight of nitrocellulose, e.g., containing 12 to 14 per cent by weight N, and 100 to 40 per cent by weight of an inert cellulose ester, e.g., cellulose acetate, or cellulose acetate butyrate.

Preferably, Component B comprises a solid granular or powdered material which can be uniformly incorporated in Component A.

Preferably at least 75% desirably at least 90% by weight of Component B is constituted by one or more heteroalicyclic nitramine compounds. Nitramine compounds are those containing at least one N-NO.sub.2 group. Heteroalicyclic nitramines bear a ring containing N-NO.sub.2 groups. Such ring or rings may contain for example from two to ten carbon atoms and from two to ten ring nitrogen atoms. Examples of preferred heteroalicyclic nitramines are RDX (cyclo -1,3,5-trimethylene-2,4,6-trinitramine, cyclonite or Hexagen), HMX (cyclo -1,3,5,7-tetramethylene -2,4,6,8-tetranitramine, Octogen) or TATND (tetranitro-tetraminodecalin) and mixtures thereof.

Preferably, Component B comprises from 50% to 100% by weight of RDX. Desirably, for propellants, the composition includes from 70 to 80 per cent by weight of RDX.

Other highly energetic filler materials may be added to the nitramine(s) of Component B, the non-nitramine component(s) providing up to 25 per cent by weight of Component B. Examples of suitable known highly energetic materials include picrite (nitroguanidine), TAGN, aromatic nitramines such as tetryl, ethylene dinitramine, and nitrate esters such as nitroglycerine (glycerol trinitrate), butane triol trinitrate or pentaerythrital tetranitrate.

Various known additives may be added to the compositions according to the present invention comprising Components A, B and C as specified above. Preferably, the additive content comprises no more than 10 per cent by weight, desirably less than 5 per cent by weight, of the combined mixture when formed into a propellant.

The additive may for example comprise one or more stabilisers, e.g. carbamite or PNMA (para-nitro-methylmethoxyaniline); and/or one or more ballistic modifiers, e.g. carbon black or lead salts; and/or one or more flash suppressants, e.g. one or more sodium or potassium salts, e.g. sodium or potassium sulphate or bicarbonate.

Preferred compositions embodying the invention for use as gun propellants comprise:

    ______________________________________
    nitrocellulose    8 to 10  per cent by weight
    cellulose acetate butyrate
                      6 to 12  per cent by weight
    RDX               70 to 80 per cent by weight
    nitroaromatic plasticiser
                      5 to 10  per cent by weight
    carbamite diethyl-diphenyl-urea
                      1        per cent by weight
    stabiliser
    ______________________________________


In this composition, the nitroaromatic plasticiser is preferably selected from one of the following:

    ______________________________________
    (a) a mixture of dinitroethylbenzene
        and trinitroethylbenzene
        containing:
        dinitroethyl-       50-64 per cent by weight
        benzene trinitroethylbenzene
                            36-50 per cent by weight;
    (b) 2,4-dinitrotoluene;
    (c) 4,6-dinitro-o-cresol;
    (d) 2,4-dinitro-m-xylene;
    ______________________________________


Compositions according to the present invention may be processed into products such as propellants by techniques which are known to those skilled in the art. The plasticiser comprising Component C is added to and absorbed by the polymer of Component A to swell and soften the polymer. If Component C includes a solid it may be melted and then added to Component A or added in a suitable solvent, e.g. acetone or ethyl acetate. Component B, preferably in a paste with an organic solvent, is blended with a mixture of Components A and C in a suitable kneader to form a homogeneous composition. Eventually, the composition produced is pressed or extruded in the form of a dough-like material through suitably shaped extrusion dies. The extrusion may be carried out using a co-rotating twin screw extrusion machine.

The product obtained by extrusion of compositions according to the present invention may be obtained in any suitable form. For example, where the product is a gun propellant, it may be obtained in the form of sticks or granules of known shape. Sticks are usually formed by cutting to a suitable length rods or strands extruded through suitable dies giving a shape including a longitudinal slot. Granules are usually similarly formed by cutting to much shorter lengths rods or sticks obtained by extrusion. Normally such granules have small holes, e.g. seven holes running lengthwise therethrough to provide suitable burning surfaces.

An important feature of certain propellant products is the web size of the product shape or configuration. This parameter, well known to those skilled in the propellants art, is the minimum thickness of propellant to be burnt through from one surface to another. For example, for a propellant product having simple tube configuration, the web thickness is the outer to inner wall thickness of the cross-sectional annulus of the tube. Web sizes of propellant products incorporating compositions embodying the invention may vary over a range according to the specific application, e.g. from 0.5 mm to 4.0 mm, although the more desirable web sizes at the lower end of this range, e.g. from 0.5 mm to 2.0 mm, will generally be suitable for most applications because the compositions generally have a low burning rate.

Examples of compositions embodying the invention and their use in the production of propellant materials will now be described.

In the following examples the appropriate Components A, B and C (as defined above) are prepared by known methods. These components are then formed into propellant products in the following general way which is known per se. The solid components comprising Component A and any minor additives, e.g. stabiliser and/or flame suppressant, are loaded as a powder into an incorporator (blender) whose blades have previously been moistened with an organic solvent. The viscous liquid comprising Component C is added to a solvent and the mixture is poured into the incorporator to which further solvent is then added. The mixture is then incorporated together for 30 minutes after which further solvent is added and the mixture is subsequently further blended for 4 hours. Cold water is continuously run through the incorporator during blending.

After processing in the incorporator the mixture formed is dried in an oven at a temperature of typically 50.degree.-90.degree. C. for a period of several hours and subsequently pressed or extruded into strands of the required shape and web size which or cut into appropriate lengths as will be readily apparent to those skilled in the art.

Products embodying the present invention comprising compositions of the following components may be made in the manner described above. In the following compositions "Nitrocellulose" means nitrocellulose containing 12.6% by weight N.

    __________________________________________________________________________
                                  Percentage
                Ingredient        by weight
    __________________________________________________________________________
    Composition 1
    Component A Cellulose acetate 20
    Component B RDX               71
    Component C 2,4-dinitrotoluene
                                  8
                Carbamite         1
    Compositions 2 to 75
    Component A Cellulose acetate 20
    Component B RDX               71
    Component C 2,4-dinitrotoluene
                                  4
                Compound X*       4
                Carbamite         1
    Composition 76
    Component A Cellulose acetate butyrate
                                  15
                Nitrocellulose    5
    Component B RDX               71
    Component C1                  9
    wherein Component C1 comprises:
    2,6-dinitrotoluene       10 pbw
    2,4-dinitrotoluene       45 pbw
    2,4,6-trinitrotoluene    45 pbw
    (where pbw = parts by weight)
    Composition 77
    Component A Cellulose acetate butyrate
                                  15
                Nitrocellulose    5
    Component B RDX               71
    Component C2                  9
    wherein Component C2 comprises:
                2,6-dinitrotoluene
                              2 pbw
                2,4-dinitrotoluene
                             54 pbw
                2,4,6-trinitrotoluene
                             44 pbw
    Composition 78
    Component A Cellulose acetate butyrate
                                  15
                Nitrocellulose    5
    Component B RDX               71
    Component C3                  9
    wherein Component C3 comprises:
    2,6-dinitrotoluene        2 pbw
    2,4-dinitrotoluene       64 pbw
    2,4,6-trinitrotoluene    34 pbw
    Composition 79
    Component A Cellulose acetate butyrate
                                  15
                Nitrocellulose    5
    Component B RDX               71
    Component C4                  9
    wherein Component C4 comprises:
    2,6-dinitro-1-ethylbenzene
                             10 pbw
    2,4-dinitro-1-ethylbenzene
                             45 pbw
    2,4,6-trinitro-1-ethylbenzene
                             45 pbw
    Composition 80
    Component A Cellulose acetate butyrate
                                  15
                Nitrocellulose    5
    Component B RDX               71
    Component C5                  9
    wherein Component C5 comprises:
    2,6-dinitro-1-ethylbenzene
                              2 pbw
    2,4-dinitro-1-ethylbenzene
                             54 pbw
    2,4,6-trinitro-1-ethylbenzene
                             44 pbw
    Composition 81
    Component A Cellulose acetate butyrate
                                  15
                Nitrocellulose    5
    Component B RDX               71
    Component C6                  9
    wherein Component C6 comprises:
    2,6-dinitro-1-ethylbenzene
                              2 pbw
    2,4-dinitro-1-ethylbenzene
                             64 pbw
    2,4,6-trinitro-1-ethylbenzene
                             34 pbw
    Composition 82
    Component A Cellulose acetate butyrate
                                  15
                Nitrocellulose    5
    Component B RDX               71
    Component C7                  9
    wherein Component C7 comprises:
    1-isopropyl-2,6-dinitrobenzene
                             10 pbw
    1-isopropyl-2,4-dinitrobenzene
                             45 pbw
    1-isopropyl-3,4,6-trinitrobenzene
                             45 pbw
    Composition 83
    Component A Cellulose acetate butyrate
                                  15
                Nitrocellulose    5
    Component B RDX               71
    Component C8                  9
    wherein Component C8 comprises:
    1-isopropyl-2,6-dinitrobenzene
                              2 pbw
    1-isopropyl-2,4-dinitrobenzene
                             54 pbw
    1-isopropyl-3,4,6-trinitrobenzene
                             44 pbw
    Composition 84
    Component A Cellulose acetate butyrate
                                  15
                Nitrocellulose    5
    Component B RDX               71
    Component C9                  9
    wherein Component C9 comprises:
    1-isopropyl-2,6-dinitrobenzene
                              2 pbw
    1-isopropyl-2,4-dinitrobenzene
                             64 pbw
    1-isopropyl-3,4,6-trinitrobenzene
                             34 pbw
    Composition 85
    Component A Cellulose acetate butyrate
                                  12
                Nitrocellulose    8.2
    Component B RDX               73.8
    Component C6                  5
    Component D Carbamite         1
    wherein Component C6 is as defined above.
    Composition 86
    Component A Cellulose acetate butyrate
                                  12
                Nitrocellulose    8.2
    Component B RDX               73.8
    Component C10                 5
    Component D Carbamite         1
    wherein Component C10 comprises:
    2,6-dinitro-1-ethylbenzene
                              2 pbw
    2,4-dinitro-1-ethylbenzene
                             48 pbw
    2,4,6-trinitro-1-ethylbenzene
                             50 pbw
    Composition 87
    Component A Cellulose acetate butyrate
                                  8
                Nitrocellulose    10
    Component B RDX               72
    Component C10                 9
    Component D Carbamite         1
    wherein Component C10 is as defined above.
    Composition 88
    Component A Cellulose acetate butyrate
                                  6
                Nitrocellulose    8
    Component B RDX               77
    Component C10                 8.5
    Component D Carbamite         0.5
    wherein Component C10 is as defined above.
    Composition 89
    Component A Cellulose acetate butyrate
                                  12
                Nitrocellulose    8.2
    Component B RDX               73.8
    Component C 4,6-dinitro-o-cresol
                                  5
    Component D Carbamite         1
    Composition 90
    Component A Cellulose acetate butyrate
                                  12
                Nitrocellulose    8.2
    Component B RDX               73.8
    Component C 2,4-dinitrotoluene
                                  5
    Component D Carbamite         1
    Composition 91
    Component A Cellulose acetate butyrate
                                  12
                Nitrocellulose    8.2
    Component B RDX               73.8
    Component C 2,4-dinitro-m-xylene
                                  5
    Component D Carbamite         1
    __________________________________________________________________________
     *wherein X is successively 1 to 68 and 70 to 75 as listed above


Compositions 1 to 91 show energy levels which are in the approximate range of 1100-1300 Joules per gram. As noted above double base compositions generally show a lower ignition temperature and lower vulnerability at the same respective energy levels.

Examples of the properties of some of the above compositions are given in Table 1 as follows, wherein

E=propellant energy in KJ per Kg,

T=propellant flame temperature in degrees Kelvin,

d=density in grammes per cm.sup.3.

                  TABLE 1
    ______________________________________
    Properties of Examples of Compositions
    Composition
    No.         E            T      d
    ______________________________________
    85          1178         3088   1.689
    86          1182         3143   1.689
    87          1216         3241   1.691
    88          1279         3453   1.706
    89          1170         3092   1.686
    90          1174         3123   1.671
    91          1168         3054   1.671
    ______________________________________


Compositions 1 to 91 show ignition temperatures which are 20-30 degrees Celsius or more above those of known double base and triple base compositions of the same energy level.

For example, a composition comprising:

    ______________________________________
    nitroglycerine
                  32% by weight
    nitrocellulose
                  32% by weight
    picrite       35% by weight
    carbamite      1% by weight
    ______________________________________


has a similar energy level to that of Composition 85, but its ignition temperature, 161.degree. C., is significantly lower than the ignition temperature, 226.degree. C., of Composition 85.


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